<!DOCTYPE html>
<html lang="zh-CN">
    <head>
        <meta charset="UTF-8" />
        <title>27_浮动-特点-行内顶部对齐</title>

        <style>
            #wrapper {
                width: 800px;

            }

            #wrapper .box {
                width: 150px;
                height: 100px;
                background-color: aqua;
                margin: 10px;

                float: left;
            } 
        </style>

    </head>
    <body>
        <div id="wrapper">
            <div class="box">1</div>
            <div class="box">2</div>
            <div class="box">3</div>
        </div>
    </body>
</html>